In just under a year, Google+, Google's social network "competitor" to Facebook and Twitter, has grown from zero users to more than 100 million monthly active users using plus.google.com. What is it, and why should you be using it?

In just under a year, Google+ (pronounced "Google Plus"), Google's social network "competitor" to Facebook and Twitter, has grown from zero users to more than 100 million monthly active users using plus.google.com. But what is it? And assuming you're already on Facebook or Twitter, why is it important to you and your business? Here are five simple reasons you should be considering Google+ as part of your social media strategy:

It's Google

Google+ really isn't a social network. It has a website, plus.google.com, which is a social network, but Google+ in and of itself is much more than that. Google+ is the social layer that binds together all Google products. The entire purpose of Google+ is to make all Google products more social.

Let's face it — just having "Google" in the title catches your attention. That's because Google is really big. Think about it — if you want to do well in a search (more on that next), Google+ makes the search more social. If you want a better presence in your customers' Gmail contacts, a Google+ presence is going to help you.

Have a local business presence? Google+ integrates your place of business into an experience that shows the friends of your customers that they frequent your company. Every Google product will have a Google+ integration, and as a result, it benefits you to have a presence on Google+.

'Social' is the new SEO

SEO, or "Search Engine Optimization," is the process of optimizing websites to index well in Google.com searches. More and more, Google is relying on social factors for influencing those results. When you log into Google.com, your search results are personalized to the things your friends have shown interest in, and the types of things you've shared.

Google+ makes SEO even easier. To start, you can tie the pictures and names of all the authors of content on your website back to their Google+ profiles. Their names and profile pictures appear next to the articles they write in Google.com search results. This makes your content stand out, even if it isn't the first one on the page.

On top of that, the more content from your website that people share and comment on within plus.google.com, the higher your content will rank both in personal search results, but also in the normal organic search results Google returns. This is one of the simplest things you can do to improve your search engine ranking on Google.com.

100 million monthly active users

Earlier this year, Google announced that it now has more than 100 million monthly active users across plus.google.com alone. This doesn't include the traffic Google+ gets across all other Google properties. (That number would be closer to 160 million monthly active users.)

No matter what anyone says, Google+ is not a graveyard. People are actively using it every month, and the community there alone is one your business could and should be targeting. This is one audience you could be tapping and bringing back to your brand to convert into real money and sales.

Google+ Hangouts

Google has a really cool feature called "Hangouts" that allows up to 10 people at a time to talk, via video chat, with each other. You can also broadcast these "Hangouts" to the public (called "Hangouts on Air"), and videos get stored on your Youtube channel. This is an opportunity for you to share what's going on within your company.